We need to find the determinant ∣A∣ of the given 3×3 matrix and then determine its minimum and maximum values.
For the matrix A=1−sinθ−1sinθ1−sinθ1sinθ1, we'll expand along Row 1:
∣A∣=1⋅1−sinθsinθ1−sinθ⋅−sinθ−1sinθ1+1⋅−sinθ−11−sinθ
Calculating each 2×2 determinant:
1−sinθsinθ1=1+sin2θ
−sinθ−1sinθ1=−sinθ+sinθ=0
−sinθ−11−sinθ=sin2θ+1
Substituting back:
∣A∣=1(1+sin2θ)−sinθ(0)+1(sin2θ+1)
∣A∣=1+sin2θ+sin2θ+1
∣A∣=2+2sin2θ
This confirms option (A) is correct.
Since 0≤sin2θ≤1:
Minimum value occurs when sin2θ=0:
∣A∣min=2+2(0)=2
Maximum value occurs when sin2θ=1:
∣A∣max=2+2(1)=4
This confirms option (D) is correct.
Options (A) and (D) are correct.